From: Francois Berder <Francois.Berder@xxxxxxxxxx> The regmap_update first reads the IOState register and then triggers a write if needed. However, GPIOS might be configured as an input so the read to IOState on this GPIO is the current state which might be random. Signed-off-by: Francois Berder <Francois.Berder@xxxxxxxxxx> --- drivers/tty/serial/sc16is7xx.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index edb5305..7f9f968 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1120,9 +1120,13 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip, struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port, gpio); struct uart_port *port = &s->p[0].port; + u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG); - sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset), - val ? BIT(offset) : 0); + if (val) + state |= BIT(offset); + else + state &= ~BIT(offset); + sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state); sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), BIT(offset)); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
